Belt grinding or polishing machine

ABSTRACT

A belt grinding or polishing machine wherein the abrasive belt is trained over several pulleys so that it includes an elongated stretch which extends between two pulleys and the outer side of which removes material from travelling workpieces. A pressure applying wheel engages the inner side of the stretch and is movable in and counter to the direction of travel of the belt as well as at right angles to the stretch to thus enable the belt to remove material from flat or more complicated surfaces.

United States Patent Stoy et al. [45] Apr. 11, 1972 [s41 BELT GRINDING 0R POLISHING [56] References Clted MACHINE UNITED STATES PATENTS [72] Inventors: Franz Stoy, Grafenberg; Heinz Eder,

Numngen bothvof Germany 2,856,737 10/1958 Evans ..5l/141 X [73] Assignee: Metabowerke KG, Closs, Rauch & Schni- Primary Examiner-Othel1M. Simpson zler, Nurji ngen. Wurttemberg, Germany Attorney-Michael S. Striker [21 Appl. No.: 8,768 A belt grinding or polishing machine wherein the abrasive belt is trained over several pulleys so that it includes an elongated 30] Foreign Application p i m stretch which extends between two pulleys and the outer side of which removes material from travelling workpieces. A pres- 12, 1969 Germany 19 07 060-] sure applying wheel engages the inner side of the stretch and is movable in and counter to the direction of travel of the belt as U-S- 51/141, 5 we as at angles to the tretch to thus enable the to 1 Illte e e e 3245 5/00, 1324b 24/00 remove material from flat or more complicated surfaces. [58] FieldofSearch ..5l/135, 138, 141,148

14 Claims, 3 Drawing Figures PATENTEDAPR 1 1 I972 SHEET 1 OF 3 INVENTOR PM W- ST'oy kfill. HEM/2 ATTORNEY P'A'TENTEUAPR 1 I I972 SHEET 2 OF 3 BY [i -l ATTORNEY BACKGROUND OF THE INVENTION The present invention relates to improvements in belt grinding or polishing machines, especially to improvements in belt grinding or polishing machines which can be used in a production line to remove material from or to otherwise treat workpieces which travel past and through several processing stations. More particularly, the invention relates to improvements in belt grinding or polishing machines of the type wherein a wheel or an analogous pressure applying member engages that stretch of the belt which removes material from workpieces.

Presently known belt grinding or polishing machines are used mainly for treatment of flat or substantially flat surfaces on metallic or other workpieces. The pressure applying wheel is normally mounted on an arm which can swivel about a fixed axis to thereby select the pressure between a workpiece and the belt. Such machines are incapable of treating workpieces whose surfaces are not at least substantially flat.

SUMMARY OF THE INVENTION An object of the invention is to provide a belt grinding or polishing machine which is more versatile than presently known machines of such character.

Another object of the invention is to provide a belt grinding or polishing machine which can be rapidly, accurately and conveniently adjusted to remove material from or to otherwise treat flat, curved, inclined, convex and many other types of surfaces with a high degree of precision.

A further object of the invention is to provide a belt grinding or polishing machine with novel and improved means for controlling the position of the pressure applying member.

An additional object of the invention is to provide a belt grinding or polishing machine whose operation can be readily programmed so that it can be used for treatment of workpieces which are conveyed through the stations of an automatic production line.

The improved machine comprises a frame, a plurality of rolls or pulleys mounted on the frame and including a first and remote second roll, an endless abrasive belt trained over the rolls so that an elongated stretch of the belt extends between the first and second rolls, drive means for rotating at least one of the rolls so that the elongated stretch travels in a predetermined direction, a pressure applying member (preferably a wheel) which normally engages the inner side of the elongated stretch, and displacing means for moving the pressure applying member in and counter to the direction of travel of the stretch.

In accordance with another feature of the invention, the displacing means supports a unit which is capable of moving the pressure applying member at right angles to the longitudinal direction of the stretch and which permits of selection of the initial position of the pressure applying member as well as of rapidly moving the member toward or away from the belt, for example, when the displacing means reaches the one and/or other end of its stroke.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved machine itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partly side elevational and partly vertical sectional view of a belt grinding or polishing machine which embodies the invention, the section being taken in the direction of arrows as seen from the line I-I of FIG. 2;

FIG. 2 is a horizontal sectional view as seen in the direction of arrows from the line Il--ll of FIG. 1; and

FIG. 3 is a transverse vertical sectional view as seen in the direction of arrows from the line III-Ill of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The machine of FIGS. 1 to 3 comprises a frame including a housing 1 and ,a supporting member 3 having a neck portion 2. The housing 1 is clamped to the neck portion 2 and the member 3 further supports an electric drive motor 4 which is located at one side of the neck portion 2 and drives a roll or pulley 5 located at the other side of the neck portion. A flange 6 of the supporting member 3 is directly or indirectly secured to a suitable column or the like (not shown) in a production line wherein the workpieces are transported in the direction indicated by arrow 14. The housing 1 carries an adjustable arm 7 for a tensioning roll or pulley 8 which is coplanar with the roll 5 and with an idler roll or pulley 10 mounted on a bracket 9 of the housing 1 at a point remote from the roll 5. An endless abrasive belt 11 is trained over the rolls 5, 8 and 10 so that its elongated lower stretch travels in the direction indicated by arrow 14 when the motor 4 is on. The outer side of the lower stretch of the belt 11 then removes material from the travelling workpieces (not shown).

In accordance with a feature of the invention, the machine further comprises a pressure applying member here shown as a wheel 13 which is coplanar with the rolls 5, 8, 10 and whose horizontal axis is parallel to the axes of these rolls and normal to the direction indicated by arrow 14. The wheel 13 is reciprocable in and counter to the direction of travel of the lower stretch of the belt 11 by a displacing unit 12 which is supported by the housing 1. The purpose of the wheel 13 is to engage the inner side of the lower stretch and to press the outer side against a travelling workpiece. The displacing unit 12 enables the wheel 13 to travel with a workpiece in the direction indicated by arrow 14. Of course, the workpiece can travel in a direction counter to that indicated by arrow 14.

The displacing unit 12 comprises a carriage 15 which is reciprocable with reference to the housing 1 and comprises pairs of wheels 16, 17, 18. The axes of the wheels 18 are vertical and the axes of the wheels 16, 17 are horizontal (see FIG. 3). The wheels l8 are located at a level between the wheels 16, 17 and the axes of all of these wheels are normal to the longitudinal direction of the lower stretch of the belt 11. The wheels 16, 17 travel along guide means 19 and the wheels 18 travel along guide means 20. The means for reciprocating the carriage 15 with reference to the guide means 19, 20 in the housing 1 comprises a pneumatic motor 21 and a hydraulic motor 36. The motor 21 includes a pneumatic cylinder which is coupled to the housing 1 and whose piston rod is connected to the carriage 15 by a link 37. The displacing unit 12 further comprises a plate-like holder 23 which is connected to the carriage 15 by a flange 22 and carries a horizontal pivot or shaft 24 for a lever 25 which supports the shaft 29 of the pressure applying wheel 13. The axes of the shafts 29, 24 are parallel to the axes of the rolls 5, 8 and 10. As shown in FIG. 1, the lefthand end portion of the lever 25 is provided with several openings or holes 26, 27, 28 each of which can receive the shaft 29 so that the initial position of the wheel 13 can be selected by the simple expedient of transferring the shaft 29 from the central hole 27 into one of the outer holes 26, 28 or vice versa. It is clear that the lever 25 can be provided with only two or with more than three holes. The purpose of such initial adjustment of the wheel 13 is to conform its position to the dimensions of workpieces which travel below the lower stretch of the belt 11.

The upper and lower guide means 19 respectively comprise pairs of parallel guide rails 30, 31 and 32, 33 which respectively define two parallel paths for the wheels 16, 17 of the carriage 15. The guide means 20 comprises two parallel guide rails 34, 35 which define a path for the wheels 18. The planes of the guide rails 30-35 (best shown in FIG. 3) are selected in such a way that the carriage 15 is guided with a high degree of accuracy.

The aforementioned hydraulic motor 36 for the carriage 15 comprises a cylinder which is articulately connected with the housing 1 and whose piston rod is connected with the carriage 15 by a link 38, or vice versa. The purpose of the motor 36 is to determine the speed of reciprocatory movement of the carriage 15; this motor can act as a brake to control the speed of movement of the carriage with the piston rod of the motor 21.

In order to regulate the pressure with which the wheel 13 bears against the inner side of the lower stretch of the belt 11, the machine further comprises a second displacing or pivoting unit which can pivot the lever 25 about the axis of the shaft 24. This second displacing unit comprises an elongated motion transmitting arm 39 which is normal to the shaft 24 and lever 25 and is pivotable with the lever 25 by means of two motors 40, 41. These motors comprise pneumatic cylinders which are mounted on the holder 23 (i.e., on the displacing unit 12) and whose piston rods can move the arm 39. The piston rod of the cylinder 40 is directly coupled to the arm 39 but the piston rod of the cylinder 41 includes an elongated portion or output member 44 provided with a slot 45 for a pin 46 at the upper end of the arm 39. The holder 23 is provided with brackets 42, 43 which respectively support the cylinders of the motors 40, 41. The motor 40 can apply the requisite pressure and can effect precise adjustments in the level of the wheel 13 because its piston rod is directly coupled to the arm 39 which is rigid with the lever 23. The purpose of the motor 41 is to rapidly lower or lift the wheel 13 at the one and/or other end of the stroke of the carriage 15. Rapid upward movement of wheel 13 results in disengagement of belt 11 from the workpiece. The maximum extent to which the lever 23 can be pivoted by the motor 41 is determined by a stop 47 here shown as a screw which is axially adjustably supported by a bracket of the carrier 23 and can be engaged by the slotted portion 44 of the motor 41. The motors 40, 41 transmit to the arm 39 force in directions which are at least nearly parallel to the direction indicated by the arrow 14.

The valves which regulate the flow of pressurized fluid to and from the motors 21, 36, 40, 41 are of conventional design and are not shown in the drawing. Such valves can insure that the carriage 15 moves in synchronism with the conveyor which transports the workpieces. The motor 4 is preferably of the variable-speed type. The arm 7 is adjustable by a pneumatic or hydraulic motor to select the initial tension of the belt 1 1.

An important advantage of the improved machine is that its belt is capable of removing material from flat as well as from more complicated surfaces on travelling workpieces. It was found that the reciprocable and pivotable pressure applying wheel 13 enables the belt 11 to treat workpieces having very simple (flat) as well as more complicated or highly complicated surfaces and that the finish of complicated surfaces is surprisingly satisfactory. Therefore, the machine can be used as a substitute for two or more special grinding or polishing machines to perform their functions in a production line or the like. Moreover, the units which reciprocate and pivot the material removing wheel 13 are of simple and compact design and are capable of insuring an infinite number of adjustments. This also enhances the versatility of the machine.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying currentknowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

1. In a grinding or polishing machine for removal of material from workpieces which are conveyed through a production line in a predetennined direction, a combination comprising a frame extending in said direction; a plurality of rolls mounted on said frame and including a first and a second roll; an

endless belt trained over said rolls and including an elongated stretch extending in said direction and having an inner side and a work engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in said predetermined direction; a rotary pressure applying member normally engaging the inner side of said stretch; displacing means for moving said pressure applying member in and counter to said predetermined direction; and means for regulating the speed of reciprocating movement of said displacing means.

2. A combination as defined in claim 1, wherein said displacing means comprises a carriage which supports said pressure applying member and a pneumatic cylinder and piston means connected to said frame and said carriage for reciprocating the latter, and wherein said means for regulating the speed of reciprocating movement of said carriage comprises hydraulic cylinder and piston means likewise connected to said frame and carriage.

3. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member comprising a rotary wheel normally engaging the inner side of said stretch and having a shaft turnably supporting said wheel; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a carriage reciprocable in said frame and a lever reciprocable with and pivotable relative to said carriage and having a plurality of openings, said shaft being received in one of said openings.

4. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaging the inner side of said stretch; first displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a carriage reciprocable in said frame and a lever supporting said pressure applying member and being reciprocable with and pivotable relative to said carriage; and second displacing means supported by said first displacing means and operable to pivot said lever with reference to said carriage substantially at right angles to said predetennined direction, said second displacing means comprising a motion transmitting element rigid with said lever and extending substantially at right angles to the pivot axis thereof, and a plurality of motors supported by said carriage and operable to pivot said lever by way of said element.

5. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising, a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaging the inner side of said stretch; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a wheeled carriage including at least one first wheel rotatable about a first axis and at least one second wheel rotatable about a second axis which is inclined with reference to said first axis, guide means on said frame and comprising elongated guide rails for said first and second wheels, and motor means for reciprocating said carriage along said guide means in and counter to said predetermined direction.

6. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaging the inner side of said stretch; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a wheeled carriage comprising three sets of aligned wheels, guide means in said frame and including three pairs of guide rails, the wheels of each of said sets being arranged to travel between one of said pairs of guide rails and the planes of one pair of guide rails being normal to the planes of the other pairs of guide rails, and motor means for reciprocating said carriage along said guide rails in and counter to said predetermined direction.

7. In a grinding or polishing machine, particularly a machin for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaging the inner side of said stretch; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a carriage reciprocable in said frame and supporting said pressure applying member, a first fluid operated cylinder and a second fluid operated cylinder located between said stretch and said first cylinder for reciprocating said carriage, each of said cylinders being connected with said frame and having a portion connected to link means provided on said carriage.

8. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame comprising a supporting member having a neck portion and a housing clampingly secured to said neck portion, said supporting member further comprising a portion connectable with a stationary part; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction, said drive means comprising a motor mounted on said supporting member and having a shaft connected to said one roll; a pressure applying member normally engaging the inner side of said stretch; and displacing means supported by said housing for moving said pressure applying member in and counter to said predetermined direction.

9. A combination as defined in claim 3, wherein the axis of said wheel is parallel to the axes of said rolls and with the pivot axis of said lever.

10. A combination as defined in claim 4, wherein said motors are arranged to transmit to said element force in directions which are substantially parallel to said predetermined direction.

II. A combination as defined in claim 4, wherein one of said motors has an output member and a pin-and-slot connection between said output member and said lever.

12. A combination as defined in claim 4, further comprising stop means for limiting the extent of pivotal movement of said lever in response to operation of said second displacing means.

13. A combination as defined in claim 5, wherein said second axis is normal to said first axis, said first and second axes being normal to said predetermined direction.

14. A combination as defined in claim 12, wherein each of said first and second wheels is guided between two of said rails. 

1. In a grinding or polishing machine for removal of material from workpieces which are conveyed through a production line in a predetermined direction, a combination comprising a frame extending in said direction; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending in said direction and having an inner side and a work engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in said predetermined direction; a rotary pressure applying member normally engaging the inner side of said stretch; displacing means for moving said pressure applying member in and counter to said predetermined direction; and means for regulating the speed of reciprocating movement of said displacing means.
 2. A combination as defined in claim 1, wherein said displacing means comprises a carriage which supports said pressure applying member and a pneumatic cylinder and piston means connected to said frame and said carriage for reciprocating the latter, and wherein said means for regulating the speed of reciprocating movement of said carriage comprises hydraulic cylinder and piston means likewise connected to said frame and carriage.
 3. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member comprising a rotary wheel normally engaging the inner side of said stretch and having a shaft turnably supporting said wheel; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a carriage reciprocable in said frame and a lever reciprocable with and pivotable relative to said carriage and having a plurality of openings, said shaft being received in one of said openings.
 4. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaginG the inner side of said stretch; first displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a carriage reciprocable in said frame and a lever supporting said pressure applying member and being reciprocable with and pivotable relative to said carriage; and second displacing means supported by said first displacing means and operable to pivot said lever with reference to said carriage substantially at right angles to said predetermined direction, said second displacing means comprising a motion transmitting element rigid with said lever and extending substantially at right angles to the pivot axis thereof, and a plurality of motors supported by said carriage and operable to pivot said lever by way of said element.
 5. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising, a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaging the inner side of said stretch; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a wheeled carriage including at least one first wheel rotatable about a first axis and at least one second wheel rotatable about a second axis which is inclined with reference to said first axis, guide means on said frame and comprising elongated guide rails for said first and second wheels, and motor means for reciprocating said carriage along said guide means in and counter to said predetermined direction.
 6. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaging the inner side of said stretch; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a wheeled carriage comprising three sets of aligned wheels, guide means in said frame and including three pairs of guide rails, the wheels of each of said sets being arranged to travel between one of said pairs of guide rails and the planes of one pair of guide rails being normal to the planes of the other pairs of guide rails, and motor means for reciprocating said carriage along said guide rails in and counter to said predetermined direction.
 7. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction; a pressure applying member normally engaging the inner side of said stretch; and displacing means for moving said pressure applying member in and counter to said predetermined direction and comprising a carriage reciprocable in said frame and supporting said pressure applying member, a firsT fluid operated cylinder and a second fluid operated cylinder located between said stretch and said first cylinder for reciprocating said carriage, each of said cylinders being connected with said frame and having a portion connected to link means provided on said carriage.
 8. In a grinding or polishing machine, particularly a machine for removal of material from workpieces which are conveyed through a production line, a combination comprising a frame comprising a supporting member having a neck portion and a housing clampingly secured to said neck portion, said supporting member further comprising a portion connectable with a stationary part; a plurality of rolls mounted on said frame and including a first and a second roll; an endless belt trained over said rolls and including an elongated stretch extending between said first and second rolls, said stretch having an inner side and a work-engaging outer side; drive means for rotating at least one of said rolls so that said stretch travels in a predetermined direction, said drive means comprising a motor mounted on said supporting member and having a shaft connected to said one roll; a pressure applying member normally engaging the inner side of said stretch; and displacing means supported by said housing for moving said pressure applying member in and counter to said predetermined direction.
 9. A combination as defined in claim 3, wherein the axis of said wheel is parallel to the axes of said rolls and with the pivot axis of said lever.
 10. A combination as defined in claim 4, wherein said motors are arranged to transmit to said element force in directions which are substantially parallel to said predetermined direction.
 11. A combination as defined in claim 4, wherein one of said motors has an output member and a pin-and-slot connection between said output member and said lever.
 12. A combination as defined in claim 4, further comprising stop means for limiting the extent of pivotal movement of said lever in response to operation of said second displacing means.
 13. A combination as defined in claim 5, wherein said second axis is normal to said first axis, said first and second axes being normal to said predetermined direction.
 14. A combination as defined in claim 12, wherein each of said first and second wheels is guided between two of said rails. 